Shell Programming and Scripting

#!/bin/bash
num1=4
num2=3
echo "Number one is $num1"
echo "Number two is $num2"
mod_final=$(( echo "num1%num2" | bc ))
echo "Final Mod is $mod_final"

num1=4
num2=3
mod_final=$(( num1%num2 ))

num1=12345678901234567890
num2=46
mod_final=$( echo "$num1%$num2" | bc )

num=$( echo "${arr[i]}%2" | bc )

#!/bin/bash
echo "This is a shell script to remove number divisible by 2 from the array"
declare -a arr=(1 6 9 12 15)
echo "Original array is ${arr[@]}"
for (( i=0; i<5; i++ ))
do
   num=$( echo "${arr[i]}%2" | bc )
   if [[ $num -eq 0 ]]
   then
       arr=(${arr[@]:0:(( $i-1))} ${arr[@]: (( $i+1 )) })
       #echo "Number divisible"
   fi
done
echo "Modified array is ${arr[@]}"

(standard_in) 1: syntax error
(standard_in) 1: syntax error